Systems and methods for batch sorbent material reuse

ABSTRACT

Methods, sorbent cartridges and cleaning devices are disclosed for refurbishing sorbent materials. In one implementation among multiple implementations, a medical fluid delivery method includes: providing a sorbent cartridge including H+ZP within a casing for a treatment; and after the treatment, refurbishing the H+ZP while maintained within the casing via (i) regenerating the non-disinfected H+ZP by flowing an acid solution through the casing, (ii) rinsing the regenerated H+ZP while maintained within the casing, (iii) disinfecting the regenerated and rinsed H+ZP by flowing a disinfecting agent through the casing, and (iv) rinsing the regenerated and disinfected H+ZP while maintained within the casing. Multiple batch sorbent refubishing implementations are also disclosed.

BACKGROUND

The present invention relates generally to medical fluid systems andmore particularly to the operation and reuse of sorbent materials fordialysis.

One drawback for known hemodialysis machines that produce treatmentfluid online or at the time of treatment is water usage. Hi-dosedialysis is preferred by certain clinicians, and may use 200 liters ormore of water per treatment. 200 liters is a lot of water for a clinicand may be especially taxing for a home dialysis treatment, where watermay be scarce and/or expensive. The equipment associated with purifyingthe water and the energy associated with heating that much water ordialysis fluid also add to the treatment cost.

Sorbent technology provides a solution to the high water usage of knownonline dialysis systems. Here, instead of discarding the used dialysisfluid exiting the dialyzer, the used dialysis fluid or effluent ispumped through a sorbent cartridge, which cleans the used dialysisfluid, removing toxic waste by-products from the used fluid. Infusate ispumped into the cleaned fluid to add back removed electrolytes and otherconstituents to restore the regenerated dialysis fluid to the same orsimilar chemical and physiological condition as fresh dialysis fluid.

Sorbent technology allows a same initial amount of water, e.g., tenliters or less, to be used over and over, to achieve the same or similareffective patient solute clearance as achieved under a single usehi-dose treatment. Thus, sorbent treatment can greatly reduce the amountof water needed for dialysis treatment.

Sorbent cartridges typically have multiple layers. The multiple layersmay include (i) a mechanical purification layer that binds or removesheavy metals, oxidants and chloramines, (ii) a urease layer thatconverts urea removed from the patient into ammonium, (iii) a zirconiumphosphate layer that binds or removes ammonium, calcium, magnesium,potassium and others, (iv) a zirconium oxide layer that binds or removesphosphate, chloride and heavy metals, and (v) an activated carbon layerthat binds or removes creatinine, uric acid and middle molecules.

The materials of the sorbent layers may be expensive, especially thesorbent layers including zirconium phosphate and zirconium oxide. Thecost of the sorbent cartridge may exceed the cost of treatment forsingle use hi-dose machines. It is accordingly desirable to reuse thematerials of the sorbent column, especially the sorbent layers includingzirconium phosphate and oxide. U.S. Pat. No. 9,707,329 (“the '329Patent”) describes routines for regenerating zirconium from a usedsorbent cartridge. FIG. 2 from the '329 Patent shows that in theillustrated example, three different filtering and washing steps arerequired. The multiple washing and filtering steps are costly and laborintensive, and at some point, may cost more than the money saved inreusing the zirconium.

A need exists accordingly to provide an improved way to regenerate usedsorbent column zirconium materials.

SUMMARY

The examples described herein disclose systems and methods to improveany treatment that uses sorbent materials to clean an effluent fluid. Inparticular, the systems and methods refurbish used sorbent materials,reducing the overall cost of the sorbent treatment. The treatmentsystems generally involve hemodialysis (“HD”) systems. The HD systems ofthe present disclosure in various embodiments include a dialysis fluidcircuit separated from a blood circuit by a dialyzer. The blood circuitincludes one or more blood pump, e.g., a blood pump pumping along thearterial line. The blood circuit includes one or more air trap, e.g., anairtrap located in the venous line. The arterial line connects to ablood inlet of the dialyzer, while the venous line connects to a bloodoutlet of the dialyzer. Other blood circuit components are describedherein.

The dialysis fluid circuit in an embodiment includes a fresh dialysisfluid pump pumping fresh and regenerated dialysis fluid to a dialysisfluid inlet of the dialyzer and a used dialysis fluid pump pumping useddialysis fluid from a dialysis fluid outlet of the dialyzer to andthrough a sorbent cartridge, which removes the waste products listedabove and acquired from the patient's blood via transfer throughsemi-permeable membranes located within the dialyzer. An infusate pumppumps infusate from an infusate source into the dialysis fluid circuitat a point downstream of the sorbent cartridge. The infusate replenishesthe cleansed dialysis fluid, restoring the dialysis fluid into a formthat may be pumped again to the dialyzer to treat the patient's blood.

The dialysis fluid circuit also includes a drain line, which enablesused dialysis fluid at the end of treatment to be pumped to drain.Various valves are located in the blood and dialysis fluid circuits tocontrol fluid flow as desired during treatment. All blood and dialysisfluid pumps and valves are operated under control of a control unit,which also accepts inputs from various sensors operating with the bloodand dialysis fluid circuits, such as pressure sensors, conductivitysensors, air detection sensors, blood detection sensors, ammonia andother chemical sensors.

Structure and methodology are provided for removing a controlled amountof ultrafiltration (“UF”) from the patient, such as a separate UF pumpor one or more weigh scales outputting to the control unit. VolumetricUF control, such as balance chambers in the dialysis fluid circuit, maybe provided alternatively. Any of the blood and dialysis fluid pumps andvalves may be operated electrometrically, e.g., via peristaltic pumpsand electrically actuated solenoid valves, or alternativelypneumatically, e.g., via volumetric pumps and pneumatic valves.

At the end of treatment using the above-described HD system, the sorbentcartridge is removed from the dialysis fluid circuit and at least someof the layers of material within the sorbent column are cleaned andregenerated according to the embodiments described below. It iscontemplated to regenerate the sorbent materials in at least twodifferent manners. In a first manner, the patient or caregiver collectsthe used sorbent cartridges. The collected used cartridges are eitherpicked up or delivered periodically to a facility where they are cleanedand regenerated in a batch manner along with used sorbent materials fromother patients. Here, the patient or caregiver receives a delivery offresh sorbent cartridges periodically. In a second manner, at least aportion of the used sorbent cartridges are cleaned and regeneratedonsite, either in a clinic or at home. In one example, any zirconiumcontaining layers are cleaned and regenerated and then repacked into thesorbent column along with new single use layers. Single use layers invarious embodiments include any one or more of a mechanical purificationlayer, a urease layer, an anion exchange layer and/or an activatedcarbon layer.

As discussed in detail below, the sorbent conditioning of the presentdisclosure may also be employed to refurbish used sorbent materials fromperitoneal dialysis (“PD”) systems and treatments.

With the above in mind, two primary embodiments are contemplated forcleaning and regenerating at least a portion of the sorbent layers, suchas the zirconium containing layers.

Batch Refurbishing

In one primary embodiment, sorbent material refurbishing is performed ina batch operation in which used sorbent materials from multiple sorbentcartridges are combined and cleaned together. The sorbent refurbishingprocess in one embodiment provides an adequate ammonium removal capacityof zirconium phosphate containing greater than 90% sodium or hydrogenexchange sites. The sorbent refurbishing in various implementationsinvolves the use of a disinfecting agent in combination with an acid,base or sodium salt treatment. The sorbent refurbishing is applicable tosorbent cartridges having different zirconium containing compartmentsprovided in a serial (e.g., layered) or parallel (e.g., used dialysisfluid flows through one or the other compartment) configuration.

It is contemplated to provide the batch sorbent refurbishing process inany one of several different implementations of the first primaryembodiment. In each case, used zirconium containing sorbent materialsfrom multiple sorbent cartridges for a single or multiple patients arecollected at a refurbishing facility. The total batch to be refurbishedin one procedure may be in the range of 10 lbs. to 10000 lbs. In a firstimplementation, (i) non-disinfected zirconium phosphate (“ZP”) isrefurbished using an acid solution, (ii) the regenerated ZP isdisinfected using a disinfecting agent, (iii) the disinfected and acidregenerated ZP is washed and filtered, (iv) the washed ZP is titrated toa desired pH, for example between and including 5.5 to 8.5, (v) thetitrated ZP is washed and filtered to a conductivity below 50 μS/cm,(vi) the washed ZP is dried, e.g., in a vacuum oven, and (vii) the driedZP is sieved using one or more sieves for one or more sorbent uses. TheZP is now ready to be reused.

In a second implementation, the titration and second washing proceduresabove are removed, such that non-disinfected zirconium phosphate (“ZP”)is (i) regenerated using an acid solution, (ii) disinfected using adisinfecting agent, (iii) washed and filtered, (iv) dried, e.g., in avacuum oven, and (v) sieved using one or more sieves for one or moresorbent uses. The ZP is now ready to be reused.

In a third implementation, the acid solution of the first implementationis replaced with a sodium based alkaline solution or a sodium saltsolution, such that (i) non-disinfected zirconium phosphate (“ZP”) isregenerated using a sodium based alkaline solution or a sodium saltsolution, (ii) the regenerated ZP is disinfected using a disinfectingagent, (iii) the disinfected and sodium regenerated ZP is washed andfiltered, (iv) the washed ZP is titrated to a desired pH, for examplebetween and including 5.5 to 8.5, (v) the titrated ZP is washed andfiltered to a conductivity below 50 μS/cm, (vi) the washed ZP is dried,e.g., in a vacuum oven, and (vii) the dried ZP is sieved using one ormore sieves for one or more sorbent uses. The ZP is now ready to bereused.

In a fourth implementation, the acid solution of the secondimplementation is replaced with a sodium based alkaline solution or asodium salt solution, such that (i) non-disinfected zirconium phosphate(“ZP”) is regenerated using a sodium based alkaline solution or a sodiumsalt solution, (ii) the regenerated ZP is disinfected using adisinfecting agent, (iii) the disinfected and sodium regenerated ZP iswashed and filtered, (iv) the washed ZP is dried, e.g., in a vacuumoven, and (v) the dried ZP is sieved using one or more sieves for one ormore sorbent uses. The ZP is now ready to be reused.

In a fifth implementation, the regenerating and disinfecting proceduresof the third implementation are reversed, such that (i) non-regeneratedZP is disinfected using a disinfecting agent, (ii) disinfected zirconiumphosphate (“ZP”) is regenerated using a sodium based alkaline solutionor a sodium salt solution, (iii) the disinfected and sodium regeneratedZP is washed and filtered, (iv) the washed ZP is titrated to a desiredpH, for example between and including 5.5 to 8.5, (v) the titrated ZP iswashed and filtered to a conductivity below 50 μS/cm, (vi) the washed ZPis dried, e.g., in a vacuum oven, and (vii) the dried ZP is sieved usingone or more sieves for one or more sorbent uses. The ZP is now ready tobe reused.

In a sixth implementation, the regenerating and disinfecting proceduresof the fourth embodiment are revered, such that (i) non-regenerated ZPis disinfected using a disinfecting agent, (ii) disinfected zirconiumphosphate (“ZP”) is regenerated using a sodium based alkaline solutionor a sodium salt solution, (iii) the disinfected and sodium regeneratedZP is washed and filtered, (iv) the washed ZP is dried, e.g., in avacuum oven, and (v) the dried ZP is sieved using one or more sieves forone or more sorbent uses. The ZP is now ready to be reused.

In any of the above implementations, the disinfecting agent may containdifferent types of chemicals. In one example, the chemical is sodiumbased, such as NaOCl in isopropyl alcohol (“IPA”). In another example,the chemical is a hydrogen based chemical, such as HOCl in IPA. A thirdexample includes IPA as the primary disinfecting agent. Also, any of theabove embodiments for preparing ZP for reuse is applicable to otherzirconium containing materials, such as zirconium oxide (“ZO”) and todifferent types of ZP, such as H⁺ZP and Na⁺ZP. Additionally, the acidsolution may be HCl, H₂SO₄, H₃PO₄, HNO₃ or acetic acid, and the sodiumbased alkaline solution or a sodium salt solution may be NaOH, NaHCO₃,Na₂CO₃ or NaCl.

The ZP made ready for reuse via any of the implementations above isplaced within the column of a sorbent cartridge, e.g., in serial orparallel fashion with other zirconium containing materials, and withreused and/or new non-zirconium layers, such as mechanical filtration,urease and activated carbon layers. The layers form a refurbishedsorbent cartridge that is deliverable to the patient along with otherrefurbished cartridges to be used over multiple treatments.

Onsite Refurbishing

In a second primary embodiment, sorbent material refurbishing isperformed in an onsite operation in which at least the zirconiumcontaining materials (e.g., ZO, H⁺ZP and Na⁺ZP) are conditioned forreuse. As with the previous primary embodiment, the sorbent refurbishingprocess of the second primary embodiment may provide an adequateammonium removal capacity of zirconium phosphate containing greater than90% sodium or hydrogen exchange sites. The sorbent refurbishing cleaningin various implementations again involves the use of a disinfectingagent in combination with an acid, base or sodium salt treatment. Thesorbent refurbishing is applicable to sorbent cartridges havingdifferent zirconium containing compartments provided in a serial (e.g.,layered) or in parallel (e.g., used dialysis fluid flows through one orthe other compartment).

A major difference between the first and second primary embodiments isthat in the batch process, the sorbent materials are removed from theirlayering casing, so that the materials from multiple sorbent cartridgesmay be mixed together and refurbished at once. In the onsite embodiment,on the other hand, the sorbent materials are left to reside within theircasing, for ease of handling and so that the patient or caregiver doesnot have to handle the sorbent materials directly.

Another difference between the first and second primary embodiments maybe that the same conditioning implementations are used for both H⁺ZP andNa⁺ZP in the first primary embodiment, while a first conditioningimplementation is used for H⁺ZP versus a second conditioningimplementation used for Na⁺ZP in the second primary embodiment. Itshould be appreciated however that the reverse may be true, namely,different conditioning implementations may be developed for H⁺ZP versusNa⁺ZP for the batch embodiment, while the same conditioningimplementation may be developed for H⁺ZP and Na⁺ZP for the onsiteembodiment.

It is contemplated to provide the onsite sorbent refurbishing cleaningprocess in any one of several different implementations. In each case,used zirconium containing sorbent layer casings are removed from thepatient's sorbent cartridge along with the non-zirconium layer casings(e.g., mechanical filtration casing, urease casing and activated carboncasing(s)). The non-zirconium layer casings may also be conditioned forreuse or discarded.

In a first implementation, which may be specific to conditioning H⁺ZP,(i) non-disinfected H⁺ZP is regenerated within its casing in a reverseflow direction, such that the casing inlet during treatment becomes thecasing outlet during regeneration and vice versa, using an acid solutionthrough the casing at a flow rate of for example 0.1 ml/min to 5 ml/minand at a temperature from about 20° C. to about 80° C., which may beperformed until the pH of the eluent (acid used to contact H⁺ZP) equalsor approaches the pH of the incoming acid solution, (ii) water is rinsedthrough the regenerated H⁺ZP within its casing (e.g., in the reverseflow direction) until conductivity of the effluent (water used to washregenerated H⁺ZP) reaches a conductivity of 100 μS/cm or less, (iii) theregenerated and rinsed H⁺ZP is disinfected via a disinfecting agent(which may contain a hydrogen based chemical such as HOCl in IPA)flowed, e.g., pumped, through the H⁺ZP casing (e.g., in the reverse flowdirection); and (iv) flow is reversed and water is rinsed through theregenerated and disinfected H⁺ZP though its casing in the normaltreatment flow direction until conductivity of the eluent (water used towash regenerated and disinfected H⁺ZP) reaches a conductivity of 100μS/cm or less. The H⁺ZP casing, e.g., after drying, is ready to bereintroduced into the sorbent cartridge and reused.

In a second implementation, which may be specific to conditioning Na⁺ZP,(i) non-disinfected Na⁺ZP is regenerated within its casing in a reverseflow direction, such that the casing inlet during treatment becomes thecasing outlet during regeneration and vice versa, and a sodium basedalkaline solution or a sodium salt solution is flowed, e.g., pumped,through the casing at a flow rate of for example 0.1 ml/min to 5 ml/minand at a temperature from about 20° C. to about 80° C., which may beperformed until the conductivity of the conductivity of the eluent(sodium solution used to contact Na⁺ZP) equals or approaches theconductivity of the incoming sodium solution, (ii) water is rinsedthrough the regenerated Na⁺ZP within its casing (e.g., in the reverseflow direction,) for a determined time (conductivity already controlledin (i)), (iii) the regenerated and rinsed Na⁺ZP is disinfected via adisinfecting agent (may contain a sodium based chemical such as NaOCl inIPA) flowed, e.g., pumped, through the Na⁺ZP casing (e.g., in thereverse flow direction); and (iv) flow is reversed and water is rinsedthrough the regenerated and disinfected Na⁺ZP casing in the normaltreatment flow direction until conductivity of the eluent (water used towash regenerated and disinfected Na⁺ZP) reaches a conductivity of 100μS/cm or less. The Na⁺ZP casing, e.g., after drying, is ready to bereintroduced into the sorbent cartridge and reused.

In a third implementation, which may also be specific to conditioningNa⁺ZP, the regeneration and disinfection procedures of the secondimplementation are reversed, such that (i) used and non-regeneratedNa⁺ZP is disinfected within its casing in a normal treatment or reverseflow direction using a disinfecting agent that may contain a sodiumbased chemical such as NaOCl in IPA, (ii) water is rinsed through thedisinfected Na⁺ZP within its casing (in normal treatment or reverse flowdirection) to remove residual chemicals until the conductivity of theeluent (water used to wash disinfected Na⁺ZP) reaches a conductivity of100 μS/cm or less; (iii) disinfected Na⁺ZP is regenerated within itscasing in the reverse flow direction, such that the casing inlet duringtreatment becomes the casing outlet during regeneration and vice versa,and a sodium based alkaline solution or a sodium salt solution isflowed, e.g., pumped, through the casing at a flow rate of for example0.1 ml/min to 5 ml/min and at a temperature from about 20° C. to about80° C., which may be performed until the conductivity of the eluent(sodium solution used to contact Na⁺ZP) equals or almost equals theconductivity of the incoming sodium solution; and (iv) flow is reversedand water is rinsed through the disinfected and regenerated Na⁺ZP thoughits casing in the normal treatment flow direction, e.g., for adetermined amount of time (conductivity already controlled in (ii) and(iii)). The Na⁺ZP casing, e.g., after drying, is now ready to bereintroduced into the sorbent cartridge and reused.

Once any or all of the H⁺ZP and Na⁺ZP casings are conditioned for reuse,the patient or caregiver inserts the reusable casings into the sorbentcartridge along with any additional casings, e.g., mechanical filtrationcasing, urease casing and/or activated carbon casing(s), which maythemselves have been conditioned for reuse or opened from a sterilepackage as a new casing. The patient or caregiver inserts the casings ina proper order and orientation, which may be aided by markings providedon the outside of sorbent cartridge. Alternatively or additionally, thecartridge and casings may be somewhat conical in shape so that thecasings only fit snugly within the cartridge when stacked in the properorder and orientation.

In an embodiment, the sorbent cartridge is closed at one end, e.g., theoutlet end, and openable at the other end, e.g., the inlet end, suchthat the user (e.g., patient, caregiver, clinician or technician) in oneembodiment only has to (i) open one side of the cartridge to remove allinner sorbent casings, (ii) condition the casings to be reused, (iii)replace the casings to be discarded, (iv) rinse the cartridge itself,(v) reinsert the refurbished and new casings into the rinsed cartridge,and (vi) close the opened end of the cartridge. In various embodiments,the inlet lid or cap may thread onto the remainder of the cartridgehousing or be held removeably fixed to the housing via releasable clips,such as spring clips. In either case, it is contemplated that the actionof applying the lid or cap to the remainder of the cartridge in turncompresses the sorbent casings together, compressing seals (e.g., o-ringseals) between the casings, such that patient effluent cannot leakbetween the casings and the inner cartridge. The seals may be capturedand carried by the casings for ease of handling when the casings areremoved from the sorbent cartridge.

The onsite operation may be performed in a dialysis clinic, at ahospital, or at a patient's home, for example. At a clinic, the sorbentcasing removal and replacement may be performed by a clinician ortechnician. At a hospital, the sorbent casing removal and replacementmay be performed by a nurse or technician. At home, the sorbent casingremoval and replacement may be performed by the patient or a caregiverfor the patient.

It is further contemplated to provide at the clinic, hospital, patient'shome or offsite one or more sorbent conditioning or refurbishing device.The device may be configured to condition or refurbish (i) one sorbentcasing at a time, (ii) multiple sorbent casings of a same type at thesame time, (iii) multiple sorbent casings of different types at the sametime, (iv) multiple sorbent casings of a same type sequentially, or (v)multiple sorbent casings of different types sequentially. The sorbentconditioning or refurbishing device accepts the one or more sorbentcasing in a sealed manner, conditions or refurbishes the one or moresorbent casing according to any of the implementations discussed abovefor the onsite primary embodiment, and informs the user when the casingis ready to be removed from the conditioning or refurbishing device andreused.

In light of the disclosure herein and without limiting the disclosure inany way, in a first aspect of the present disclosure, which may becombined with any other aspect listed herein unless specified otherwise,a medical fluid delivery method includes providing a sorbent cartridgeincluding zirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for atreatment; and after the treatment, refurbishing the ZP or ZO via thesteps of (i) regenerating the non-disinfected ZP or ZO using an acidsolution, (ii) disinfecting the regenerated ZP or ZO using adisinfecting agent, (iii) at least one of washing or filtering theregenerated and disinfected ZP or ZO, (iv) titrating the washed orfiltered ZP or ZO to a desired pH, (v) at least one of washing orfiltering the titrated ZP or ZO until a desired conductivity is reached,(vi) drying the rewashed or refiltered ZP or ZO, and (vii) sieving thedried ZP or ZO.

In a second aspect of the present disclosure, which may be combined withany other aspect listed herein unless specified otherwise, at least oneof (a) the acid solution is HCl, H₂SO₄, H₃PO₄, HNO₃ or acetic acid or(b) the disinfecting agent (i) is sodium based, such as including NaOCl,(ii) is hydrogen based, such as including HOCl, or (iii) includesisopropyl alcohol (“IPA”).

In a third aspect of the present disclosure, which may be combined withany other aspect listed herein unless specified otherwise, the desiredpH is between and including 5.5 to 8.5.

In a fourth aspect of the present disclosure, which may be combined withany other aspect listed herein unless specified otherwise, the desiredconductivity is below 50 μS/cm.

In a fifth aspect of the present disclosure, which may be combined withany other aspect listed herein unless specified otherwise, refurbishingthe ZP or ZO includes combining ZP or ZO removed from multiple sorbentcartridges before regeneration.

In a sixth aspect of the present disclosure, which may be combined withany other aspect listed herein unless specified otherwise, a medicalfluid delivery method includes providing a sorbent cartridge includingzirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for a treatment;and after the treatment, refurbishing the ZP or ZO via (i) regeneratingthe non-disinfected ZP or ZO using an acid solution, (ii) disinfectingthe regenerated ZP or ZO using a disinfecting agent, (iii) at least oneof washing or filtering the regenerated and disinfected ZP or ZO, (iv)drying the washed or filtered ZP or ZO, and (v) sieving the dried ZP orZO.

In a seventh aspect of the present disclosure, which may be combinedwith the sixth aspect and any other aspect listed herein unlessspecified otherwise, at least one of (a) the acid solution is HCl,H₂SO₄, H₃PO₄, HNO₃ or acetic acid or (b) the disinfecting agent (i) issodium based, such as including NaOCl, (ii) is hydrogen based, such asincluding HOCl, or (iii) includes isopropyl alcohol (“IPA”).

In an eighth aspect of the present disclosure, which may be combinedwith the sixth aspect and any other aspect listed herein unlessspecified otherwise, refurbishing the ZP or ZO includes combining ZP orZO removed from multiple sorbent cartridges before regeneration.

In a ninth aspect of the present disclosure, which may be combined withany other aspect listed herein unless specified otherwise, a medicalfluid delivery method includes providing a sorbent cartridge includingzirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for a treatment;and after the treatment, refurbishing the ZP or ZO via (i) regeneratingthe non-disinfected ZP or ZO using a sodium based alkaline solution or asodium salt solution, (ii) disinfecting the regenerated ZP or ZO using adisinfecting agent, (iii) at least one of washing or filtering theregenerated and disinfected ZP or ZO, (iv) titrating the washed orfiltered ZP or ZO to a desired pH, (v) at least one of washing orfiltering the titrated ZP or ZO until a desired conductivity is reached,(vi) drying the rewashed or refiltered ZP or ZO, and (vii) sieving thedried ZP or ZO.

In a tenth aspect of the present disclosure, which may be combined withthe ninth aspect and any other aspect listed herein unless specifiedotherwise, at least one of (a) the sodium based alkaline solution or asodium salt solution is NaOH, NaHCO₃, Na₂CO₃ or NaCl or (b) thedisinfecting agent (i) is sodium based, such as including NaOCl, (ii) ishydrogen based, such as including HOCl, or (iii) includes isopropylalcohol (“IPA”).

In an eleventh aspect of the present disclosure, which may be combinedwith the ninth aspect and any other aspect listed herein unlessspecified otherwise, the desired pH is between and including 5.5 to 8.5.

In a twelfth aspect of the present disclosure, which may be combinedwith the ninth aspect and any other aspect listed herein unlessspecified otherwise, the desired conductivity is below 50 μS/cm.

In a thirteenth aspect of the present disclosure, which may be combinedwith the ninth aspect and any other aspect listed herein unlessspecified otherwise, refurbishing the ZP or ZO includes combining ZP orZO removed from multiple sorbent cartridges before regeneration.

In a fourteenth aspect of the present disclosure, which may be combinedwith any other aspect listed herein unless specified otherwise, amedical fluid delivery method includes providing a sorbent cartridgeincluding zirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for atreatment; and after the treatment, refurbishing the ZP or ZO via (i)regenerating the non-disinfected ZP or ZO using a sodium based alkalinesolution or a sodium salt solution, (ii) disinfecting the regenerated ZPor ZO using a disinfecting agent, (iii) at least one of washing orfiltering the regenerated and disinfected ZP or ZO, (iv) drying thewashed or filtered ZP or ZO, and (v) sieving the dried ZP or ZO.

In a fifteenth aspect of the present disclosure, which may be combinedwith the fourteenth aspect and any other aspect listed herein unlessspecified otherwise, at least one of (a) the sodium based alkalinesolution or a sodium salt solution is NaOH, NaHCO₃, Na₂CO₃ or NaCl or(b) the disinfecting agent (i) is sodium based, such as including NaOCl,(ii) is hydrogen based, such as including HOCl, or (iii) includesisopropyl alcohol (“IPA”).

In a sixteenth aspect of the present disclosure, which may be combinedwith the fourteenth aspect and any other aspect listed herein unlessspecified otherwise, refurbishing the ZP or ZO includes combining ZP orZO removed from multiple sorbent cartridges before regeneration.

In a seventeenth aspect of the present disclosure, which may be combinedwith any other aspect listed herein unless specified otherwise, amedical fluid delivery method includes providing a sorbent cartridgeincluding zirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for atreatment; and after the treatment, refurbishing the ZP or ZO via (i)disinfecting the non-regenerated ZP or ZO using a disinfecting agent,(ii) regenerating the disinfected ZP or ZO using a sodium based alkalinesolution or a sodium salt solution, (iii) at least one of washing orfiltering the disinfected and regenerated ZP or ZO, (iv) titrating thewashed or filtered ZP or ZO to a desired pH, (v) at least one of washingor filtering the titrated ZP or ZO until a desired conductivity isreached, (vi) drying the rewashed or refiltered ZP or ZO, and (vii)sieving the dried ZP or ZO.

In an eighteenth aspect of the present disclosure, which may be combinedwith the seventeenth aspect and any other aspect listed herein unlessspecified otherwise, at least one of (a) the sodium based alkalinesolution or a sodium salt solution is NaOH, NaHCO₃, Na₂CO₃ or NaCl or(b) the disinfecting agent (i) is sodium based, such as including NaOCl,(ii) is hydrogen based, such as including HOCl or (iii) includesisopropyl alcohol (“IPA”).

In a nineteenth aspect of the present disclosure, which may be combinedwith the seventeenth aspect and any other aspect listed herein unlessspecified otherwise, the desired pH is between and including 5.5 to 8.5.

In a twentieth aspect of the present disclosure, which may be combinedwith the seventeenth aspect and any other aspect listed herein unlessspecified otherwise, the desired conductivity is below 50 μS/cm.

In a twenty-first aspect of the present disclosure, which may becombined with the seventeenth aspect and any other aspect listed hereinunless specified otherwise, refurbishing the ZP or ZO includes combiningZP or ZO removed from multiple sorbent cartridges before disinfection.

In a twenty-second aspect of the present disclosure, which may becombined with any other aspect listed herein unless specified otherwise,a medical fluid delivery method includes providing a sorbent cartridgeincluding zirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for atreatment; and after the treatment, refurbishing the ZP or ZO via (i)disinfecting the non-regenerated ZP or ZO using a disinfecting agent,(ii) regenerating the disinfected ZP or ZO using a sodium based alkalinesolution or a sodium salt solution, (iii) at least one of washing orfiltering the disinfected and regenerated ZP or ZO, (iv) drying thewashed or filtered ZP or ZO, and (v) sieving the dried ZP or ZO.

In a twenty-third aspect of the present disclosure, which may becombined with the twenty-second aspect and any other aspect listedherein unless specified otherwise, at least one of (a) the sodium basedalkaline solution or a sodium salt solution is NaOH, NaHCO₃, Na₂CO₃ orNaCl or (b) the disinfecting agent (i) is sodium based, such asincluding NaOCl, (ii) is hydrogen based, such as including HOCl or (iii)includes isopropyl alcohol (“IPA”).

In a twenty-fourth aspect of the present disclosure, which may becombined with the twenty-second aspect and any other aspect listedherein unless specified otherwise, refurbishing the ZP or ZO includescombining ZP or ZO removed from multiple sorbent cartridges beforedisinfection.

In a twenty-fifth aspect of the present disclosure, any of the structureand functionality disclosed in connection with FIGS. 1 to 15 may beincluded or combined with any of the other structure and functionalitydisclosed in connection with FIGS. 1 to 15.

In light of the present disclosure and the above aspects, it istherefore an advantage of the present disclosure to provide an improvedused sorbent material regeneration system and method.

It is another advantage of the present disclosure to provide an improvedused sorbent material regeneration system and method operable in a batchmanner.

It is a further advantage of the present disclosure to provide animproved used sorbent material regeneration system and method that isoperable onsite.

It is still another advantage of the present disclosure to provide asorbent cartridge that is readily disassembled and reassembled to removeused sorbent material casings and replace refurbished or new sorbentmaterial casings.

It is a further advantage of the present disclosure to provide animproved used sorbent material regeneration system and method having asorbent conditioning or refurbishing device that accepts used sorbentmaterial casings and generates refurbished sorbent material casings.

The advantages discussed herein may be found in one, or some, andperhaps not all of the embodiments disclosed herein. Additional featuresand advantages are described herein, and will be apparent from, thefollowing Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view of one embodiment of a sorbent hemodialysis(“HD”) system that may employ any of the sorbent refurbishing techniquesof the present disclosure.

FIG. 2 is a schematic view of one embodiment of a sorbent peritonealdialysis (“PD”) system that may employ any of the sorbent refurbishingtechniques of the present disclosure.

FIG. 3 is a schematic diagram of a first batch sorbent implementation ofthe present disclosure.

FIG. 4 is a schematic diagram of a second batch sorbent refurbishingimplementation of the present disclosure.

FIG. 5 is a schematic diagram of a third batch sorbent refurbishingimplementation of the present disclosure.

FIG. 6 is a schematic diagram of a fourth batch sorbent refurbishingimplementation of the present disclosure.

FIG. 7 is a schematic diagram of a fifth batch sorbent refurbishingimplementation of the present disclosure.

FIG. 8 is a schematic diagram of a sixth batch sorbent refurbishingimplementation of the present disclosure.

FIG. 9 is a schematic diagram of an example parallel path sorbentcartridge formed via certain implementations of the batch refurbishingof the present disclosure.

FIG. 10 is a schematic diagram of an example parallel path sorbentcartridge formed via certain implementations of the onsite refurbishingof the present disclosure.

FIG. 11 is a schematic diagram of an onsite H⁺ZP sorbent refurbishingimplementation of the present disclosure.

FIG. 12 is a schematic diagram of a first onsite Na⁺ZP sorbentrefurbishing implementation of the present disclosure.

FIG. 13 is a schematic diagram of a second onsite Na⁺ZP sorbentrefurbishing of the present disclosure.

FIG. 14 is an exploded perspective view of one embodiment of a sorbentcartridge that may be used with the onsite sorbent refurbishing of thepresent disclosure.

FIG. 15 is a fluid schematic view of one embodiment of an onsite sorbentcasing refurbishing device of the present disclosure.

DETAILED DESCRIPTION System Overview

Referring now to the drawings and in particular to FIG. 1, a medicalfluid delivery system, such as a hemodialysis (“HD”) system 10 isillustrated. In the illustrated embodiment, HD system 10 includes ablood circuit 20 separated from a dialysis fluid circuit 40 by adialyzer 18. Blood circuit 20 connects to the vascular system of patient12. In particular, blood circuit 20 includes an arterial line 22 havingan arterial needle that allows blood to be removed from patient 12.Arterial line 22 runs to an inlet of the blood compartment of dialyzer18. Blood circuit 20 also includes a venous line 24 having an venousneedle that allows blood cleansed via dialyzer 18 to be retuned topatient 12. Venous line 24 runs to an outlet of the blood compartment ofdialyzer 18.

In the illustrated embodiment, a blood pump 26 is provided alongarterial line 22. Blood pump 26 removes blood from patient 12 viaarterial line 22 under negative pressure and pumps the blood underpositive pressure through the reminder of the arterial line, the bloodcompartment of dialyzer 18, and venous line 24, back to patient 12.Blood pump 26 may be an electromechanical peristaltic pump or avolumetric or diaphragm pump, e.g., driven via pneumatic pressure. Bloodcircuit 20 includes one or more air trap, e.g., airtrap 28, located invenous line 24, to remove any air from the blood before it is returnedto patient 12. A venous line air detector 30 and occluder or valve 32are provided to clamp or occlude venous line 24 in the case that air isdetected via air detector 30. Pressure sensors 34 a to 34 c are providedto monitor arterial line negative pressure, arterial line positivepressure and venous line positive pressure, respectively. Blood circuit20 may also include a hematocrit or blood consistency sensor (notillustrated).

FIG. 1 further illustrates that dialysis fluid circuit 40 includes afresh dialysis fluid line 42, which delivers fresh dialysis fluid (e.g.,dialysis fluid cleansed via sorbent cartridge 100) to an inlet of adialysis fluid compartment of dialyzer 18. Dialysis fluid circuit 40includes a used dialysis fluid line 44, which removes used dialysisfluid from an outlet of the dialysis fluid compartment of dialyzer 18.Sorbent cartridge 100 separates fresh dialysis fluid line 42 from useddialysis fluid line 44. One or both of the fresh and used dialysis fluidlines may be provided with a pump. In the illustrated embodiment, afresh dialysis fluid pump 46 operates with or along fresh dialysis fluidline 42, while used dialysis fluid pump 48 operates with or along useddialysis fluid line 44. Fresh and used dialysis fluid pumps 46 and 48may be electromechanical peristaltic pumps or volumetric or diaphragmpumps, e.g., driven via pneumatic pressure.

Pressure sensors 52 a to 52 d are located along dialysis fluid circuit40 to detect, respectively, (a) negative pressure between dialyzer 18and used dialysis fluid pump 48, (b) positive pressure between useddialysis fluid pump 48 and sorbent cartridge 100, (c) negative pressurebetween sorbent cartridge 100 and fresh dialysis fluid pump 46, and (d)positive pressure between fresh dialysis fluid pump 46 and dialyzer 18.A blood leak detector 54 is located in used dialysis fluid line 44 justdownstream of dialyzer 18 to look for leaks in the hollow fibermicroporous membranes of the dialyzer 18. An ammonia sensor 74 (and/orother physiological sensor) is located along fresh dialysis fluid line42 and is used to ensure that regenerated dialysis fluid from sorbentcartridge 100 will be effective to remove toxins from patient 12 whenreturned to the patient.

An initial fluid supply and UF container 56 is connected fluidly vialine 58 to used dialysis fluid line 44 upstream of used dialysis fluidpump 48. Used dialysis fluid pump 48 pulls an initial supply of dialysisfluid from container 56 into dialysis fluid circuit 40 to prime thecircuit and then for use to clean the blood of patient 12. The initialsupply of HD dialysis fluid is prepared in one embodiment byadministering liquid or dried HD concentrate (e.g., acid andbicarbonate) into container 56 and then pouring a specified amount ofpotable water, e.g., six to ten liters, into container 56 to mix (anddissolve if needed) the concentrate. Pumps 46 and 48 are operated topump the initial supply of dialysis fluid through sorbent cartridge 100to purify the initial supply to an appropriate level before the initialsupply reaches dialyzer 18. A valve 60 a is located along supply line 58to selectively allow or not allow initial fluid supply and UF container56 to communicate fluidly with dialysis fluid circuit 40.

An infusate container 62 is connected fluidly via line 64 to freshdialysis fluid line 42 downstream of sorbent cartridge 100. An infusatepump 66, such as a peristaltic or a volumetric pump, is located alonginfusate line 64 between infusate container 62 and fresh dialysis fluidline 42. Sorbent cartridge 100 also absorbs desirable components thatneed to be replenished. Infusate pump 66 meters a desired amount ofinfusate (containing electrolytes and other constituents) that placesthe dialysis fluid regenerated via sorbent cartridge 100 in the same orsimilar chemical and physiological condition as fresh dialysis fluidfrom container 56. A valve 60 b is located along infusate line 64 toselectively allow or not allow infusate container 62 to communicatefluidly with dialysis fluid circuit 40.

In the illustrated embodiment, dialysis fluid circuit 40 includes adrain line 68, which extends from used dialysis fluid line 44 andenables used dialysis fluid at the end of treatment to be pumped to adrain 70, such as a drain bag or a house drain (e.g., a toilet or bathtub). A valve 60 c is located along drain line 68, which along withvalves 60 d and 60 e, selectively allows or occludes flow through thedrain line to drain 70.

Valves 60 d and 60 e are located in fresh dialysis fluid line 42 andused dialysis fluid line 44, respectively, to selectively allow orocclude flow through those lines. Any valve discussed herein, includingany of valves 60 a to 60 e may be an electrically actuated solenoidpinch valve that operates directly with the associated tube or line orbe a disposable-cassette based valve that is opened or closedpneumatically or electromechanically.

Structure and methodology are provided for removing a controlled amountof ultrafiltration (“UF”) from patient 12, such as a separate UF pump orone or more weigh scales outputting to control unit 50. In theillustrated embodiment, a weigh scale 72 is located beneath initialfluid supply and UF container 56. Weigh scale 72 at the beginning oftreatment weighs the initial supply of fresh dialysis fluid withincontainer 56 to know that the fresh dialysis fluid has been proportionedproperly with the amount of wet or dry dialysis fluid concentrateprovided and delivered into fresh dialysis fluid supply container 56.During treatment, valves 60 a and 60 e are toggled periodically toenable a prescribed amount of used dialysis fluid to be diverted as UFinto now UF container 56, wherein the prescribed amount is obtainedusing weigh scale 72. At the end of treatment, the remaining useddialysis fluid is delivered instead to drain 70 via drain line 68 anddrain valve 60 c. Other types of volumetric control, such as balancechambers in dialysis fluid circuit 40 may be used alternatively tocontrol UF and the amount of fresh and used dialysis fluid delivered toand removed from dialyzer 18.

In the illustrated embodiment as indicated by the dashed electricaland/or signal lines, all blood and dialysis fluid pumps and valves (suchas valves 32 and 60 a to 60 e) are operated under control of a controlunit 50, which also accepts inputs from each of the sensors describedabove operating with blood circuit 20 and dialysis fluid circuit 40,such as, pressure sensors 34 a to 34 c and 52 a to 52 d, conductivitysensors, air detection sensor 30, blood detection sensor 54, ammonia 74and/or other chemical sensors.

At the end of treatment using above-described HD system 10, sorbentcartridge 100 is removed from dialysis fluid circuit 40 and at leastsome of the layers of material within a sorbent column of the cartridgeare cleaned and regenerated according to the embodiments describedbelow.

Referring now to FIG. 2, the sorbent conditioning of the presentdisclosure may also be employed to refurbish used sorbent materials fromperitoneal dialysis (“PD”) treatments using a PD system, such as PDsystem 110. PD system 110 operates with a patient 112. In system 110,dialyzer 18 is not used, however, sorbent column 100 is used. PD system110 is described as a continuous flow peritoneal dialysis (“CFPD”),however, the sorbent cleaning of the present disclosure is equallyapplicable to continuous cycling peritoneal dialysis (“CCPD”) and tidalPD. With CFPD, patient 112 is provided with a dual lumen catheter 114,which allows fresh or regenerated dialysis fluid to be pumped alongfresh dialysis fluid line 116 to one lumen of dual lumen catheter 114,while used dialysis fluid is removed via the other lumen of dual lumencatheter 114 into used dialysis fluid line 118. Fresh dialysis fluidline 116 is separated from used dialysis fluid line 118 via sorbentcartridge 100.

In the illustrated embodiment, a single PD fluid pump 120 is providedalong used dialysis fluid line 118 to pull used dialysis fluid frompatient 112 via dual lumen catheter 114, and to push the used dialysisfluid through sorbent cartridge 100, and cleansed dialysis fluid fromcartridge 100, through fresh dialysis fluid line 116, back to patient112 via dual lumen catheter 114. A separate infusate pump 122 is used tometer a desired amount of PD electrolytes and make-up constituents intofresh dialysis fluid line 116 via a PD infusate container 124 and aninfusate line 126 leading to the fresh dialysis fluid line.

A supply and UF line 128 leads from an initial fluid supply and UFcontainer 130 to used dialysis fluid line 118 upstream of PD fluid pump120. An initial supply of PD dialysis fluid is prepared in oneembodiment by administering liquid or dried PD concentrate (e.g.,dextrose/glucose and buffer) into container 130 and then delivering aspecified amount of potable water, e.g., six to ten liters, into thecontainer to mix (and dissolve if needed) the concentrate. PD fluid pump120 is operated so as to pump the initial supply of dialysis fluidthrough sorbent cartridge 100 to purify the initial supply to anappropriate level before the initial supply reaches patient 112.

A weigh scale 132 is located beneath initial fluid supply and UFcontainer 130 to proportion the PD concentrate and added potable watercorrectly and to allow a desired amount of UF to be removed from patient112 over the course of treatment as described above for HD system 10.Weigh scale 132 as illustrated may be used additionally if needed (or adifferent scale may be used) with drain bag 136, so that with valves 140b and 140 d closed and valve 140 c open, PD fluid pump 120 can drive adesired amount of UF into the drain bag. The alternative UF controlembodiments described above for HD system 10 may also be used withpresent PD system 110.

In the illustrated embodiment, system 110 also includes a drain line 134leading to a drain container 136. Drain line 134 in one embodimentextends from used dialysis fluid line 118 at a location downstream of PDfluid pump 120. At the end of treatment, whatever dialysis fluid has notbeen pumped to UF container 130 is pumped instead to drain container136. Drain line 134 leads alternatively to a house drain, such as atoilet or bathtub. Alternatively, all PD fluid and patient UF isdelivered to drain bag 136 at the end of treatment.

PD system 110 in the illustrated embodiment includes multiple sensors,such as pressure sensors 138 a and 138 b located along fresh dialysisfluid line 116 and used dialysis fluid line 118, respectively, which areused to ensure that the negative pressure (pressure sensor 138 b) andthe positive pressure (pressure sensor 138 a) applied to patient 112 viaPD fluid pump 120 are within acceptable limits. An ammonia sensor 142(and/or other physiological sensor) is located along fresh dialysisfluid line 116 and is used to ensure that regenerated dialysis fluidfrom sorbent cartridge 100 will be effective to remove toxins frompatient 112 when returned to the patient.

Valve 140 a is located along supply and UF line 128 to selectively allowor not allow initial fluid supply and UF container 130 to communicatefluidly with used dialysis fluid line 118. A valve 140 b is locatedalong infusate line 126 to selectively allow or not allow infusatecontainer 124 to communicate fluidly with fresh dialysis fluid line 116.A valve 140 c is located along drain line 134 to selectively allow orocclude flow through the drain line. Valves 140 d and 140 e are locatedin fresh dialysis fluid line 116 and used dialysis fluid lines 118,respectively, to selectively allow or occlude flow through those lines.As mentioned above, any valve discussed herein, including any of valves140 a to 140 e may be an electrically actuated solenoid pinch valve thatoperates directly with the associated tube or line, or be adisposable-cassette based valve that is opened or closed pneumaticallyor electromechanically.

In the illustrated embodiment as indicated by the dashed electricaland/or signal lines, all dialysis fluid pumps and valves (such as valves140 a to 140 e) are operated under control of a control unit 150, whichalso accepts inputs from each of the sensors described above operatingwith fresh dialysis fluid line 116 and used dialysis fluid lines 118,such as, pressure sensors 138 a and 138 b, conductivity sensors, airdetection sensors, ammonia 142 and/or other chemical sensors.

An alternative PD system (not illustrated) uses a structure similar toHD system 10, which includes dialyzer 18. Here, blood circuit 20 isreplaced with a patient PD fluid circuit. Dialysis fluid circuit 40 usesPD dialysis fluid to clean the patient PD fluid in circuit 20. Sorbentcartridge 100 is located in PD dialysis fluid circuit 40 to cleansewaste and toxins from the PD dialysis fluid, which receives waste andtoxins from the patient PD fluid in circuit 20 via dialyzer 18 throughosmosis. All structure and functionality described above for HD system10, such as for the pumps, valves and sensors, is applicable to thealternative dual loop CFPD system.

At the end of treatment using above-described HD system 10, sorbentcartridge 100 is removed from dialysis fluid circuit 40 and at leastsome of the layers of material within a sorbent column of the cartridgeare cleaned and regenerated according to the embodiments describedbelow.

Sorbent Material Refurbishing

With any of HD system 10, PD system 110 or the PD system using thestructure of HD system 10 just described, it is contemplated torefurbished the sorbent materials in at least two different manners. Ina first manner, patient 12, 112 or the caregiver collects used sorbentcartridges 100. The collected used cartridges are either picked up ordelivered periodically to a facility where they are cleaned andregenerated in a batch manner along with used sorbent materials fromother patients. Here, patient 12, 112 or the caregiver receives adelivery of fresh sorbent cartridges 100 periodically. In a secondmanner, at least a portion of used sorbent cartridges 100 are cleanedand regenerated onsite, either in a clinic or at home. In one example,any zirconium containing layers are cleaned and regenerated and thenrepacked into the sorbent column of cartridge 100 along with new singleuse layers. Single use layers in various embodiments include any one ormore of a mechanical purification layer, a urease layer, an anionexchange layer and/or an activated carbon layer.

Batch Refurbishing

In the batch refurbishing primary embodiment, used sorbent materialsfrom multiple sorbent cartridges 100 are combined and cleaned together.The sorbent cleaning process in one embodiment provides an adequateammonium removal capacity of zirconium phosphate containing greater than90% sodium or hydrogen exchange sites. The sorbent cleaning in variousimplementations involves the use of a disinfecting agent in combinationwith an acid, base or sodium salt treatment. The sorbent cleaning isapplicable to sorbent cartridges 100 having different zirconiumcontaining compartments provided in a serial (e.g., layered) or inparallel (e.g., used dialysis fluid flows through one or the othercompartment).

It is contemplated to provide the batch sorbent refurbishing process inany one of a plurality of different implementations of the first primaryembodiment. In each case, used zirconium containing sorbent materialsfrom multiple sorbent cartridges 100 used by a single or multiplepatients 12, 112 is collected at a refurbishing facility. The totalbatch to be refurbishing one procedure may be in the range of 10 lbs. to1000 lbs.

In each of the batch refurbishing implementations discussed below,example reagents include:

-   10 mM NH4Cl/PD solution (NH4Cl spiked PD Dianeal® solution),-   30 mM NH4Cl/PD solution (NH4Cl spiked PD Dianeal® solution),-   7 mM NH4Cl/PD solution (NH4Cl spiked PD Dianeal® solution),-   0.1N NaCl,-   0.1N HCL,-   0.1N NaOH, and-   0.5M NaHCO3+0.1N NaOH-   The Dianeal® low calcium (2.5 mEq/L) peritoneal dialysis solution    with 2.5% dextrose, catalog #5B9776. Each 100 ml contains    -   2.5 g dextrose hydrous USP,    -   538 mg sodium chloride USP,    -   448 mg sodium lactate,    -   18.3 mg calcium chloride USP,    -   5.08 mg magnesium chloride USP, and    -   pH 5.2-   mEq/L:    -   sodium—132,    -   calcium—2.5,    -   magnesium—0.5,    -   chloride—95,    -   lactate 40, and    -   osmolarity 395 mOsmol/L

In each of the batch refurbishing implementations discussed below,example sorbents include:

Bottle Sorbent Lot 1 Terio ZP 40051 commercial zirconium phospahte batch2 JiangXi Zp 20160113 commercial zirconium phospahte batch 3 Baxter ZPNA commercial zirconium phospahte batch 4 REDY ZP B-488 commercialzirconium phospahte batch 5 Terio ZP 40054 commercial zirconiumphospahte batch 6 Terio ZP 40055 commercial zirconium phospahte batch 7JiangXi Zp 20160116 commercial zirconium phospahte batch 8 JiangXi Zp20160228 commercial zirconium phospahte batch 9 CarboChem 100316-1commercial zirconium phospahte batch

In each of the batch refurbishing implementations discussed below,example equipment includes:

-   three VWR tube rotator, 10136-084,-   one Rotoflex rotator, Argos, cat #R2000,-   50 ml Centrifuge tube, VWR,-   2 ml Micro tube, VWR, catalog #211-0092,-   universal fit screw caps with O-ring, VWR, catalog #211-0131,    211-0129,-   balance, L13831, L25833,-   pipette, RL-10532,-   stop watch, L31016,-   HPLC pump,-   bio-scale MT columns, bio-rad catalog number: 751-0081,-   1M NaCl, 0.5M NaHCO3, 2M NaHCO3, 1M CH3COONa,-   1M HCl, 0.5M HCl, and-   1M NaOH, 0.5M NaOH

One example static sorbent sorption capacity test for the batchrefurbishing embodiment includes:

-   1. Dry zirconium phosphate (ZP) is contacted with PD low calcium    dialysate solution at the ration of 7 g sorbent in 1 L PD solution    containing 10 mM of ammonium chloride.-   2. The suspension is mixed using stirring bar at room temperature    for 1 hr.-   3. 1.0 ml control samples were taken from the 10 mM NH4Cl/PD.-   4. Three test samples were collected from supernatant at time=1    hour.-   5. The control and test samples were sent for chemical analysis to    measure the concentration of NH₄ ⁺, BUN, Bicarbonate, Na⁺,    phosphorus, Ca²⁺ and Mg²⁺, K⁺ and pH.-   6. NH₄ ⁺ sorption capacity in zirconium phosphate is calculated.

Example data analysis for a static sorbent sorption capacity test forthe batch refurbishing embodiment includes:

Static Sorption Test

NH₄ ⁺ adsorption is obtained by equation 1:

$\begin{matrix}{{{{q = \frac{\left( {c_{i} - c_{e}} \right) \cdot L}{ZP}}{{where}\text{:}}q\text{:}\mspace{14mu}{adsorbed}\mspace{14mu}{NH}_{4}^{+}\mspace{11mu}\left( {{mmol}\mspace{14mu}{NH}_{4}^{+}\text{/}g\mspace{14mu}{ZP}} \right)},{C_{i}\text{:}\mspace{14mu}{initial}\mspace{14mu}{concentration}\mspace{14mu}{of}\mspace{14mu}{NH}_{4}^{+}\mspace{14mu}{in}\mspace{14mu}{dialysate}\mspace{14mu}{solution}\mspace{14mu}\left( {{mmol}\text{/}L} \right)},{C_{e}\text{:}\mspace{14mu}{concentration}\mspace{14mu}{of}\mspace{14mu}{NH}_{4}^{+}\mspace{14mu}{at}\mspace{14mu}{{equilibrium}{\;\mspace{11mu}}\left( {{mmol}\text{/}L} \right)}},{L\text{:}\mspace{14mu}{volume}\mspace{14mu}{of}\mspace{14mu}{test}\mspace{14mu}{solution}},{and}}{{ZP}\text{:}\mspace{14mu}{dosage}\mspace{14mu}{of}\mspace{14mu}{ZP}\mspace{14mu}{added}\mspace{14mu}{to}\mspace{14mu}{the}\mspace{14mu}{bottle}\mspace{11mu}({grams})}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

Dynamic Sorption Test

NH₄ ⁺ adsorption is obtained by equation 2:

$\begin{matrix}{{q = \frac{\left\lbrack {{NH}\; 4\text{+}} \right\rbrack \times Q \times {BT} \times 0.001}{ZP}}{{where}\text{:}}{{q\text{:}\mspace{14mu}{adsorbed}\mspace{14mu}{NH4}\text{+}\mspace{11mu}\left( {{mmol}\mspace{14mu}{NH}_{4}^{+}\text{/}g\mspace{14mu}{ZP}} \right)},{\left\lbrack {NH}_{4}^{+} \right\rbrack\text{:}\mspace{14mu}{feed}\mspace{14mu}{concentration}\mspace{14mu}{of}\mspace{14mu}{NH}_{4}^{+}\mspace{14mu}{in}\mspace{14mu}{dialysate}\mspace{14mu}{solution}\mspace{14mu}\left( {{mmol}\text{/}L} \right)},{Q\text{:}\mspace{14mu}{flow}\mspace{14mu}{rate}\mspace{11mu}\left( {{ml}\text{/}\min} \right)},{{BT}\text{:}\mspace{14mu}{NH}_{4}^{+}\mspace{14mu}{break}\mspace{14mu}{through}\mspace{14mu}{time}\mspace{11mu}\left( \min \right)},{and}}{{ZP}\text{:}\mspace{14mu}{dosage}\mspace{14mu}{of}\mspace{14mu}{ZP}\mspace{14mu}{added}\mspace{14mu}{to}\mspace{14mu}{the}\mspace{14mu}{bottle}\mspace{11mu}({grams})}} & {{Equation}\mspace{14mu} 2}\end{matrix}$

Referring now to FIG. 3, a first batch sorbent refurbishingimplementation is illustrated by method 160. At oval 162, method 160begins. At block 164, non-disinfected zirconium phosphate (“ZP”) isremoved and collected from the relevant casings in the columns of eachof a plurality of used sorbent cartridges 100 returned to the sorbentrefurbishing facility. The collected and combined non-disinfected ZP isregenerated using an acid solution.

At block 166, the regenerated ZP is disinfected using a disinfectingagent. The disinfecting agent in various examples includes any one ormore of various types of chemicals. One is a sodium based chemical suchas NaOCl in isopropyl alcohol (“IPA”). The other is hydrogen basedchemical such as HOCl in IPA. A third includes IPA as the primarydisinfecting agent.

At block 168, the disinfected and acid regenerated ZP is washed andfiltered. Washing and filtering is performed in one example by flowingwater through the disinfected and acid refurbished ZP, rinsing anyresidue from the disinfection and the acid regeneration.

At block 170, the washed ZP is titrated to a desired pH, for example, toa pH between and including 5.5 to 8.5. Titration may be performed usingan analyte, an indicator and a pH meter. The titration is performed tothe entire batch in one embodiment. The washed ZP is stirred in aqueoussuspension at room temperature and the pH is continuosly monitored. ThepH of the suspension is adjusted by adding small aliquotes of dilutedbasic solution (e.g. 0.1 N NaOH and/or 0.5 M NaHCO3) If the pH risesabove the desired range, small aliquotes of diluted acid solution (e.g.0.1 N HCl) can be added.

At block 172, the titrated ZP is washed and filtered to a conductivitybelow 50 μS/cm. Washing and filtering is performed again in one exampleusing water, which subsequent to washing and filtering the ZP is flowed,e.g., pumped, past a temperature-compensated conductivity probe thatreads out to a conductivity meter. Once the meter reads below 50 μS/cm,the washing and filtering at block 172 may be stopped.

At block 174, the washed ZP is dried, e.g., in a vacuum oven at 120° C.or greater for a duration known to completely dry the washed mass of ZP.

At block 176, the dried ZP is sieved using one or more sieves for one ormore sorbent uses. Sieving produces ZP granules having at least aminimum desired smallest diameter needed for the intended use. Thesieved ZP granules are then placed back into a casing, which may havealso been disinfected. The casing is placed in a desired order within acolumn of a refurbished sorbent cartridge 100, which is now ready to beused again in treatment, and may be shipped to a patient's home orclinic.

At oval 178, method 160 ends.

Referring now to FIG. 4, a second batch sorbent refurbishingimplementation is illustrated by method 180. In method 180, thetitration at block 170 and the second washing procedure at block 172 ofmethod 170 are removed. At oval 182, method 180 begins.

At block 184, non-disinfected zirconium phosphate (“ZP”) is removed andcollected from the relevant casings in the columns of each of aplurality of used sorbent cartridges 100 returned to the sorbentrefurbishing facility. The collected and combined non-disinfected ZP isregenerated using an acid solution.

At block 186, the regenerated ZP is disinfected using a disinfectingagent. The disinfecting agent includes any one or more of (i) a sodiumbased chemical such as NaOCl in isopropyl alcohol (“IPA”), (ii) ahydrogen based chemical such as HOCl in IPA or (iii) IPA as the primarydisinfectant.

At block 188, the disinfected and acid regenerated ZP is washed andfiltered, which in an example is performed by flowing water through thedisinfected and acid regenerated ZP, rinsing any residue from thedisinfection and the acid regeneration.

At block 190, the washed ZP is dried, e.g., in a vacuum oven at 120° C.or greater for a duration known to completely dry the washed mass of ZP.

At block 192, the dried ZP is sieved using one or more sieves for one ormore sorbent uses. The sieved ZP granules are then placed back into acasing, which may have also been disinfected. The casing is placed in adesired order within a column of a refurbished sorbent cartridge 100,which is now ready to be used again in treatment, and may be shipped toa patient's home or clinic.

At oval 194, method 180 ends.

Referring now to FIG. 5, a third batch sorbent refurbishingimplementation is illustrated by method 200. In method 200, the acidsolution of method 160 is replaced with a sodium based alkaline solutionor a sodium salt solution. At oval 202, method 200 begins.

At block 204, non-disinfected zirconium phosphate (“ZP”) is removed andcollected from the relevant casings in the columns of each of aplurality of used sorbent cartridges 100 returned to the sorbentrefurbishing facility. The collected and combined non-disinfected ZP isregenerated using a sodium based alkaline solution or a sodium saltsolution.

At block 206, the regenerated ZP is disinfected using a disinfectingagent. The disinfecting agent includes any one or more of (i) a sodiumbased chemical such as NaOCl in isopropyl alcohol (“IPA”), (ii) ahydrogen based chemical such as HOCl in IPA, or (iii) IPA as the primarydisinfecting agent.

At block 208, the disinfected and sodium regenerated ZP is washed andfiltered, which in an example is performed by flowing water through thedisinfected and sodium regenerated ZP, rinsing any residue from thedisinfection and the acid regeneration.

At block 210, the washed ZP is titrated to a desired pH, for example, toa pH between and including 5.5 to 8.5. Titration may be performed usingan analyte, an indicator and a pH meter. The titration is performed tothe entire batch in one embodiment. The washed ZP is stirred in aqueoussuspension at room temperature and the pH is continuosly monitored. ThepH of the suspension is adjusted by adding small aliquotes of dilutedbasic solution (e.g. 0.1 N NaOH and/or 0.5 M NaHCO3) If the pH risesabove the desired range, small aliquotes of diluted acid solution (e.g.0.1 N HCl) can be added.

At block 212, the titrated ZP is washed and filtered to a conductivitybelow 50 μS/cm. Washing and filtering is performed again in one exampleusing water, which subsequent to washing and filtering the ZP is flowed,e.g., pumped, past a temperature-compensated conductivity probe thatreads out to a conductivity meter. Once the meter reads below 50 μS/cm,the washing and filtering at block 172 may be stopped.

At block 214, the washed ZP is dried, e.g., in a vacuum oven at 120° C.or greater for a duration known to completely dry the washed mass of ZP.

At block 216, the dried ZP is sieved using one or more sieves for one ormore sorbent uses. The sieved ZP granules are then placed back into acasing, which may have also been disinfected. The casing is placed in adesired order within a column of a refurbished sorbent cartridge 100,which is now ready to be used again in treatment, and may be shipped toa patient's home or clinic.

At oval 218, method 200 ends.

Referring now to FIG. 6, a fourth batch sorbent refurbishingimplementation is illustrated by method 220. In method 220, the acidsolution of method 180 is replaced with a sodium based alkaline solutionor a sodium salt solution. At oval 222, method 220 begins.

At block 224, non-disinfected zirconium phosphate (“ZP”) is removed andcollected from the relevant casings in the columns of each of aplurality of used sorbent cartridges 100 returned to the sorbentrefurbishing facility. The collected and combined non-disinfected ZP isregenerated using a sodium based alkaline solution or a sodium saltsolution.

At block 226, the regenerated ZP is disinfected using a disinfectingagent. The disinfecting agent includes any one or both of (i) a sodiumbased chemical such as NaOCl in isopropyl alcohol (“IPA”), (ii) ahydrogen based chemical such as HOCl in IPA, or (iii) IPA as the primarydisinfecting agent.

At block 228, the disinfected and sodium regenerated ZP is washed andfiltered, which in an example is performed by flowing water through thedisinfected and sodium regenerated ZP, rinsing any residue from thedisinfection and the sodium regeneration.

At block 230, the washed ZP is dried, e.g., in a vacuum oven at 120° C.or greater for a duration known to completely dry the washed mass of ZP.

At block 232, the dried ZP is sieved using one or more sieves for one ormore sorbent uses. The sieved ZP granules are then placed back into acasing, which may have also been disinfected. The casing is placed in adesired order within a column of a refurbished sorbent cartridge 100,which is now ready to be used again in treatment, and may be shipped toa patient's home or clinic.

At oval 234, method 220 ends.

Referring now to FIG. 7, a fifth batch sorbent refurbishingimplementation is illustrated by method 240. In method 240, theregenerating and disinfecting procedures at blocks 204 and 206 of method200 are reversed. At oval 242, method 240 begins.

At block 244, non-regenerated zirconium phosphate (“ZP”) is removed andcollected from the relevant casings in the columns of each of aplurality of used sorbent cartridges 100 returned to the sorbentrefurbishing facility. The collected and combined non-regenerated ZP isdisinfected using a disinfecting agent. The disinfecting agent includesany one or both of (i) a sodium based chemical such as NaOCl inisopropyl alcohol (“IPA”), (ii) a hydrogen based chemical such as HOClin IPA, or (iii) IPA as the primary disinfecting agent.

At block 246, the disinfected ZP is regenerated using a sodium basedalkaline solution or a sodium salt solution.

At block 248, the disinfected and sodium regenerated ZP is washed andfiltered, which in an example is performed by flowing water through thedisinfected and sodium regenerated ZP, rinsing any residue from thedisinfection and the sodium regeneration.

At block 250, the washed ZP is titrated to a desired pH, for example, toa pH between and including 5.5 to 8.5. Titration may be performed usingan analyte, an indicator and a pH meter. The titration is performed tothe entire batch in one embodiment. The washed ZP is stirred in aqueoussuspension at room temperature and the pH is continuosly monitored. ThepH of the suspension is adjusted by adding small aliquotes of dilutedbasic solution (e.g. 0.1 N NaOH and/or 0.5 M NaHCO3) If the pH risesabove the desired range, small aliquotes of diluted acid solution (e.g.0.1 N HCl) can be added.

At block 252, the titrated ZP is washed and filtered to a conductivitybelow 50 μS/cm. Washing and filtering is performed again in one exampleusing water, which subsequent to washing and filtering the ZP is flowed,e.g., pumped, past a temperature-compensated conductivity probe thatreads out to a conductivity meter. Once the meter reads below 50 μS/cm,the washing and filtering at block 172 may be stopped.

At block 254, the washed ZP is dried, e.g., in a vacuum oven at 120° C.or greater for a duration known to completely dry the washed mass of ZP.

At block 256, the dried ZP is sieved using one or more sieves for one ormore sorbent uses. The sieved ZP granules are then placed back into acasing, which may have also been disinfected. The casing is placed in adesired order within a column of a refurbished cartridge 100, which isnow ready to be used again in treatment, and may be shipped to apatient's home or clinic.

At oval 258, method 240 ends.

Referring now to FIG. 8, a sixth batch sorbent refurbishingimplementation is illustrated by method 260. In method 260, theregenerating and disinfecting procedures at blocks 224 and 226 of method220 are reversed. At oval 262, method 260 begins.

At block 264, non-regenerated zirconium phosphate (“ZP”) is removed andcollected from the relevant casings in the columns of each of aplurality of used sorbent cartridges 100 returned to the sorbentrefurbishing facility. The collected and combined non-regenerated ZP isdisinfected using a disinfecting agent. The disinfecting agent includesany one or both of (i) a sodium based chemical such as NaOCl inisopropyl alcohol (“IPA”), (ii) a hydrogen based chemical such as HOClin IPA, or (iii) IPA as the primary disinfecting agent.

At block 266, the disinfected ZP is regenerated using a sodium basedalkaline solution or a sodium salt solution.

At block 268, the disinfected and sodium regenerated ZP is washed andfiltered, which in an example is performed by flowing water through thedisinfected and sodium regenerated ZP, rinsing any residue from thedisinfection and the sodium regeneration.

At block 270, the washed ZP is dried, e.g., in a vacuum oven at 120° C.or greater for a duration known to completely dry the washed mass of ZP.

At block 272, the dried ZP is sieved using one or more sieves for one ormore sorbent uses. The sieved ZP granules are then placed back into acasing, which may have also been disinfected. The casing is placed in adesired order within a column of a refurbished sorbent cartridge 100,which is now ready to be used again in treatment, and may be shipped toa patient's home or clinic.

At oval 274, method 260 ends.

In any of the above implementations for refurbishing ZP for reuse isapplicable to other zirconium containing materials, such as zirconiumoxide (“ZO”) and to different types of ZP, such as H⁺ZP and Na⁺ZP. Thelayers form a refurbished sorbent cartridge 100 that is deliverable tothe patient along with other refurbished cartridges 100 to be used overmultiple treatments.

Moreover, the ZP made ready for reuse via any of the implementationsabove may be placed within the column of sorbent cartridge 100 in aserial or parallel fashion with other zirconium containing materials,and with reused and/or new non-zirconium layers, such as mechanicalfiltration, urease, anion and activated carbon exchange layers. Forexample, ZP from any of methods 160, 200 or 240 forms an Na/Hrefurbished sorbent, which may be packed in a casing spanning the entirediameter of the column of sorbent cartridge 100 for reuse.

In any of the batch implementations, the acid solution may be HCl,H₂SO₄, H₃PO₄, HNO₃ or acetic acid, while the sodium based alkalinesolution or a sodium salt solution may be NaOH, NaHCO₃, Na₂CO₃ or NaCl.

ZP from method 180 contains greater than 90% hydrogen ion exchangesites. The ZP from method 180 may be packed in an H+ZP casing for aparallel cartridge 100 as shown in FIG. 9. ZP from methods 220 and 260contains greater than 90% sodium ion exchange sites. The ZP from methods220 and 260 may be packed in Na+ZP column for parallel cartridge asshown in FIG. 9.

Onsite Refurbishing

In a second primary embodiment, sorbent material refurbishing isperformed in an onsite operation in which at least the zirconiumcontaining materials (e.g., ZO, H⁺ZP and Na⁺ZP) are conditioned forreuse. As with the previous primary embodiment, the sorbent refurbishingprocess of the second primary embodiment may provide an adequateammonium removal capacity of zirconium phosphate containing greater than90% sodium or hydrogen exchange sites. The sorbent refurbishing invarious implementations again involves the use of a disinfecting agentin combination with an acid, base or sodium salt treatment. The sorbentrefurbishing is applicable to sorbent cartridges 100 having differentzirconium containing compartments provided in a serial (e.g., layered)or in parallel (e.g., used dialysis fluid flows through one or the othercompartment).

A primary difference between the first and second primary embodiments isthat in the batch process, the sorbent materials are removed from theirlayering casing, so that the materials from multiple sorbent cartridges100 may be mixed together and cleaned at once. In the onsite embodiment,on the other hand, the sorbent materials are left to reside within theircasings, for ease of handling and so that the patient or caregiver doesnot have to handle the sorbent materials directly.

In each of the onsite refurbishing implementations discussed below,example reagents include:

-   7 mM NH4Cl/PD solution (NH4Cl spiked PD Dianeal® solution),-   0.1N NaCl,-   0.1N HCL,-   0.1N NaOH, and-   0.5M NaHCO₃+0.1 N NaOH-   The Dianeal® low calcium (2.5 mEq/L) peritoneal dialysis solution    with 2.5% dextrose, catalog #5B9776. Each 100 ml contains:    -   2.5 g dextrose hydrous USP,    -   538 mg sodium chloride USP,    -   448 mg sodium lactate,    -   18.3 mg calcium chloride USP,    -   5.08 mg magnesium chloride USP, and    -   pH 5.2-   mEq/L:    -   sodium 132,    -   calcium 2.5,    -   magnesium 0.5,    -   chloride 95,    -   lactate 40, and    -   osmolarity 395 mOsmol/L

In each of the onsite refurbishing implementations discussed below,example sorbents include:

Bottle Sorbent lot 1 Terio ZP 40051 commercial zirconium phospahte batch2 JiangXi Zp 20160113 commercial zirconium phospahte batch 3 Baxter ZPNA commercial zirconium phospahte batch 4 REDY ZP B-488 commercialzirconium phospahte batch 5 Terio ZP 40054 commercial zirconiumphospahte batch 6 Terio ZP 40055 commercial zirconium phospahte batch 7JiangXi Zp 20160116 commercial zirconium phospahte batch 8 JiangXi Zp20160228 commercial zirconium phospahte batch 9 CarboChem 100316-1commercial zirconium phospahte batch

In each of the onsite refurbishing implementations discussed below,example equipment includes:

-   2 ml Micro tube, VWR, catalog #211-0092,-   universal fit screw caps with O-ring, VWR, catalog #211-0131,    211-0129,-   balance, L13831, L25833,-   pipette, RL-10532,-   stop watch, L31016,-   HPLC pump,-   bio-Scale MT columns, Bio-Rad catalog number: 751-0081,-   1M NaCl, 0.5M NaHCO3, 2M NaHCO3, 1M CH3COONa,-   0.1 N HCl, and-   0.1N NaOH

One example sorbent sorption capacity test for the onsite refurbishingembodiment uses a parallel chamber sorbent cartridge 100 illustrated inFIG. 10. Here, sorbent cartridge 100 includes a cartridge housing 80forming the column of the cartridge. Housing 80 holds an inlet activatedcarbon and filter casing 96 and an outlet activated carbon and filtercasing 98. A urease casing 102 is located just downstream from inletactivated carbon and filter casing 96. An anion exchange resin casing104 is located just upstream from outlet activated carbon and filtercasing 98. In between urease casing 102 and anion exchange resin casing104 are two parallel ZP casings, namely, an H⁺ZP casing 106 and an Na⁺ZPcasing 108.

It should be appreciated that H⁺ZP casing 106 and an Na⁺ZP casing 108may be moved collectively to a different order, e.g., downstream ofanion exchange resin casing 104 or upstream of urease casing 102. Itshould also be appreciated that parallel ZP casings do not have to beprovided and that a single H⁺ZP casing 106 or Na⁺ZP casing 108 sized tospan the entire diameter of housing 80 may be provided instead. Theanalysis below applies equally to a sorbent cartridge 100 having onlyone of H⁺ZP casing 106 or Na⁺ZP casing 108, or a sorbent cartridge 100having serially juxtaposed H⁺ZP and Na⁺ZP casings 106 and 108.

One example sorption capacity test for sorbent cartridge 100 illustratedin FIG. 10 includes:

-   1. 7 mM NH₄Cl/PD solution is passed through the ZP column/cartridge    at 1.5 ml/min flow rate.-   2. 1 ml eluent samples are collected at different time points and    are sent for chemical analysis to measure the concentration of NH₄    ⁺, BUN, Bicarb, Na⁺, P, Ca²⁺ and Mg²⁺, K⁺ and pH.-   3. Ammonia break through point is determined at the time point where    [NH₃] concentration of eluent sample reaches 1 mmol/L. NH₃ sorption    capacity is calculated according to equation 3 below.

One example column regeneration procedure for sorbent cartridge 100illustrated in FIG. 10 includes:

-   1. Rinse parallel columns, e.g., pump water through both columns to    rinse the excess sugar, debris and ion.-   2. Regenerate and disinfect both columns, e.g., reverse flow path    for regeneration.-   3. The regeneration and disinfection solution for H⁺ZP contains    acid.-   4. The regeneration and disinfection solution for Na⁺ZP contains    sodium.

Example data analysis for a static sorbent sorption capacity test forthe onsite refurbishing embodiment includes:

Dynamic Sorption Test

NH₄ ⁺ adsorption is obtained by equation 3:

$\begin{matrix}{{q = \frac{\left\lbrack {{NH}\; 4\text{+}} \right\rbrack \times Q \times {BT} \times 0.001}{ZP}}{{where}\text{:}}{{q\text{:}\mspace{14mu}{Adsorbed}\mspace{14mu}{NH}_{3}\;\left( {{mmol}\mspace{14mu}{NH}_{4}^{+}\text{/}g\mspace{14mu}{ZP}} \right)},{\left\lbrack {NH}_{4}^{+} \right\rbrack\text{:}\mspace{14mu}{feed}\mspace{14mu}{concentration}\mspace{14mu}{of}\mspace{14mu}{NH}_{4}^{+}\mspace{14mu}{in}\mspace{14mu}{dialysate}\mspace{14mu}{solution}\mspace{14mu}\left( {{mmol}\text{/}L} \right)},{Q\text{:}\mspace{14mu}{flow}\mspace{14mu}{rate}\mspace{11mu}\left( {{ml}\text{/}\min} \right)},{{BT}\text{:}\mspace{14mu}{NH}_{4}^{+}\mspace{14mu}{break}\mspace{14mu}{through}\mspace{14mu}{time}\mspace{11mu}\left( \min \right)},{and}}{{ZP}\text{:}\mspace{14mu}{dosage}\mspace{14mu}{of}\mspace{14mu}{ZP}\mspace{14mu}{added}\mspace{14mu}{to}\mspace{14mu}{the}\mspace{14mu}{bottle}\mspace{11mu}({grams})}} & {{Equation}\mspace{14mu} 3}\end{matrix}$

Referring now to FIG. 11, one onsite sorbent refurbishing implementationfor H⁺ZP casing 106 is illustrated by method 280. At oval 282, method280 begins. At block 284, non-disinfected H⁺ZP is regenerated withincasing 106 in a reverse flow direction to operational flow throughsorbent cartridge 100. Here, an inlet of casing 106 during treatmentbecomes instead the outlet of casing 106 outlet during regeneration andvice versa. An acid solution is flowed, e.g., pumped, through casing 106at a flow rate of for example 0.1 ml/min to 5 ml/min and at atemperature from about 20° C. to about 80° C. The acid wash is performedin one example until the pH of the eluent (acid that has contacted H⁺ZP)equals or almost equals the pH of the incoming acid solution.

At block 286, water is rinsed (e.g., pumped) through the regeneratedH⁺ZP within casing 106 (e.g., in the reverse flow direction) until aconductivity of the effluent (water used to wash regenerated H⁺ZP)reaches a conductivity of 100 μS/cm or less.

At block 288, the regenerated and rinsed H⁺ZP is disinfected via adisinfecting agent, which in various examples includes a hydrogen basedchemical, such as HOCl in IPA, flowed, e.g., pumped, through the H⁺ZPcasing 106 (e.g., in the reverse flow direction).

At block 290, flow is reversed and water is rinsed, e.g., pumped throughthe regenerated and disinfected H⁺ZP casing 106 in the normal treatmentflow direction until conductivity of the eluent (water used to washregenerated and disinfected H⁺ZP) reaches a conductivity of 100 μS/cm orless.

At block 292, H⁺ZP casing 106 is dried and is ready to be reintroducedinto sorbent cartridge 100 and reused. At oval 294, method 280 ends.

Referring now to FIG. 12, one onsite sorbent refurbishing implementationfor Na⁺ZP casing 108 is illustrated by method 300. At oval 302, method300 begins. At block 304, non-disinfected Na⁺ZP is regenerated withinits casing in a reverse-to-operational flow direction, such that aninlet of Na⁺ZP casing 108 during treatment becomes the outlet of Na⁺ZPcasing 108 during regeneration and vice versa. A sodium based alkalinesolution or a sodium salt solution is flowed, e.g., pumped, throughNa⁺ZP casing 108 at a flow rate of for example 0.1 ml/min to 5 ml/min,and at a temperature from about 20° C. to about 80° C. The sodiumregeneration may be performed until the conductivity of the eluent(sodium solution that has contacted Na⁺ZP) equals or almost equals theconductivity of the incoming sodium solution.

At block 306, water is rinsed through the regenerated Na⁺ZP within itscasing 108 (e.g., in the reverse flow direction,) for a determined timeknowing that the conductivity has already been controlled at block 384.

At block 308, the regenerated and rinsed Na⁺ZP is disinfected via adisinfecting agent, which in various examples includes a sodium basedchemical, such as NaOCl in IPA, flowed, e.g., pumped, through the Na⁺ZPcasing (e.g., in the reverse flow direction).

At block 310, flow is reversed and water is rinsed, e.g., pumped,through the regenerated and disinfected Na⁺ZP within its casing 108 inthe normal treatment flow direction until conductivity of the eluent(water used to wash regenerated and disinfected Na⁺ZP) reaches aconductivity of 100 μS/cm or less.

At block 312, Na⁺ZP casing 108 is dried and is ready to be reintroducedinto sorbent cartridge 100 and reused. At oval 314, method 300 ends.

Referring now to FIG. 13, a second onsite sorbent refurbishingimplementation for Na⁺ZP casing 108 is illustrated by method 320. Here,the regeneration and disinfection procedures of method 300 are reversed.At oval 322, method 300 begins. At block 324, used and non-regeneratedNa⁺ZP is disinfected within its casing 108 in a normal treatment orreverse flow direction, e.g., via pumping, using a disinfecting agentthat may contain a sodium based chemical such as NaOCl in IPA.

At block 326, water is rinsed, e.g., pumped, through the disinfectedNa⁺ZP within its casing 108, in a normal treatment or reverse flowdirection, to remove residual disinfecting chemicals until theconductivity of the eluent (water used to wash disinfected Na⁺ZP)reaches a conductivity of 100 μS/cm or less.

At block 328, disinfected Na⁺ZP is regenerated within its casing 108 inthe reverse flow direction, such that the inlet of casing 108 duringtreatment becomes the outlet of casing 108 during regeneration and viceversa. A sodium based alkaline solution or a sodium salt solution isflowed, e.g., pumped, through casing 108 at a flow rate of for example0.1 ml/min to 5 ml/min and at a temperature from about 20° C. to about80° C. Regeneration is performed in one embodiment until theconductivity of the eluent (sodium solution that has contacted Na⁺ZP)equals or almost equals the conductivity of the incoming sodiumsolution.

At block 330, flow is reversed and water is rinsed, e.g., pumped,through the disinfected and regenerated Na⁺ZP within its casing 108 inthe normal treatment flow direction, e.g., for a determined amount oftime (knowing that conductivity has already been controlled at blocks326 and 328.

At block 332, Na⁺ZP casing 108 is dried and is ready to be reintroducedinto sorbent cartridge 100 and reused. At oval 334, method 300 ends.

Once any or all of the H⁺ZP and Na⁺ZP casings 106 and 108 arerefurbished or conditioned for reuse, patient 12, 112 or caregiverinserts the reusable casings into cartridge housing 80 of sorbentcartridge 100 along with any additional casings, e.g., mechanicalfiltration casing, urease casing, anion exchange casing, and/oractivated carbon casing(s), which may themselves have been conditionedfor reuse or opened from a sterile package as a new casing. Patient 12,112 or caregiver inserts all casings in a proper order and orientation,which may be aided by markings provided on the outside of sorbentcartridge. Alternatively or additionally, housing 80 of cartridge 100and the casings may be somewhat conical in shape so that the casingsonly fit snugly within the cartridge when stacked in the proper orderand orientation.

In any of the onsite implementations, the acid solution may be HCl,H₂SO₄, H₃PO₄, HNO₃ or acetic acid, while the sodium based alkalinesolution or a sodium salt solution may be NaOH, NaHCO₃, Na₂CO₃ or NaCl.

Referring now to FIG. 14, in an embodiment, housing 80 of sorbentcartridge 100 is closed at one end 82, e.g., the fluid outlet end, andopenable at the other end via a lid or cap 84, e.g., the fluid inletend, such that the user (e.g., patient 12, 112, caregiver, clinician ortechnician) in one embodiment only has to (i) open one side of cartridge100 to remove all inner sorbent casings, e.g., casings 106 and 108, (ii)condition the casings 106 and 108, to be reused, (iii) replace thecasings to be discarded, (iv) rinse housing 80 itself, (v) reinsert therefurbished casings, e.g., casings 106 and 108, and new casings intorinsed housing 80, and (vi) close the lid or cap 84 onto the open end ofhousing 80.

In various embodiments, inlet lid or cap 84 of the opened end may threadonto the remainder of cartridge housing 80 via threads 86 or translateonto the remainder of housing 80 and be held removeably fixed to housingvia releasable clips or latches 88, such as spring clips or latches. Ineither case, an o-ring seal 90 may be provided between lid or cap 84 andhousing 80, which is compressed when lid or cap 84 is fitted to housing80. Further, in either case it is contemplated that the action ofapplying the lid or cap 84 to the remainder of the housing 80 in turncompresses the sorbent casings 94, 96, 102, 106, 108, 104 and 98together, compressing seals 92 (e.g., o-ring seals) between the casings,such that patient effluent cannot leak between the casings and the innercartridge. Seals 92 as illustrated may be captured and carried by thecasings for ease of handling when the casings are removed from thesorbent cartridge. Exit end casing 98 may have or capture seals 92 onboth sides, wherein the seal on the downstream side seals against closedend 82. Alternatively, closed end 82 includes a seal 92 for sealingagainst exit end casing 98. Seal 92 of inlet end casing 94 in anembodiment seals against an inside of cap 84.

In FIG. 14, housing 80 of sorbent cartridge 100 holds seven casings,including a mechanical filter casing 94, followed by inlet activatedcarbon and filter casing 96, followed by urease casing 102, followed byH^(+ZP) casing 106, followed by Na⁺ZP casing 108 (or casings 106 and 108could be placed in parallel as illustrated above), followed by anionexchange resin casing 104, followed by outlet activated carbon andfilter casing 98. Sorbent cartridge 100 alternatively holds more or lessand/or different casings and/or in different orders. The casings asillustrated are slightly conical in shape and fit together in logicalorder and orientation to form an overall conical shape, which is theonly shape that will fit into like sized and shaped conical housing 80.As mentioned above, sorbent cartridge 100 is configured such thatthreading or compressing lid or cap 84 onto the remainder of housing 80compresses (i) seal 90 between lid or cap 84 and the remainder ofhousing 80 and (ii) seals 92 between casings 94, 96, 102, 106, 108, 104and 98 (and casing 94 to lid or cap 84 and casing 98 to closed end 82).

In the illustrated embodiment, cap 84 includes an inlet 76 for useddialysis fluid, an initial batch of dialysis fluid, or water needingpurification. Closed end 82 of housing 80 includes an outlet 78 foroutputting cleansed dialysis fluid (or water). Seals 92 ensure thatfluid entering through inlet 76 cannot flow around the outside of thecasings between the casings and housing 80. Inlet 76 and outlet 78 maybe of the same or different type, including a straight or tapered portto which a tube compression fits, a luer fitting, a threaded fitting, ora ferruled compression fitting. FIG. 14 also illustrates that thecircular inlet and outlet faces of casings 94, 96, 102, 106, 108, 104and 98, within seals 92, may each be made of a mesh material (same ordifferent mesh sizes for the different casings) that allow fluid to flowthrough the faces, but that trap the sorbent or filter material locatedwithin the casings. The mesh material also allows at least some of thecasings to be regenerated after use.

The onsite operation may be performed in a dialysis clinic, at ahospital, or at a patient's home, for example. At a clinic, the sorbentcasing removal and replacement may be performed by a clinician ortechnician. At a hospital, the sorbent casing removal and replacementmay be performed by a nurse or technician. At home, the sorbent casingremoval and replacement may be performed by patient 12, 112 or acaregiver for the patient.

Referring now to FIG. 15, it is further contemplated to provide at theclinic, hospital, or patient's home one or more sorbent conditioning orrefurbishing device 350. Device 350 may be configured to condition orrefurbish (i) one sorbent casing at a time, (ii) multiple sorbentcasings of a same type at the same time, (iii) multiple sorbent casingsof different types at the same time (as illustrated in FIG. 15), (iv)multiple sorbent casings of a same type sequentially, or (v) multiplesorbent casings of different types sequentially. Sorbent conditioning orrefurbishing device 350 accepts the one or more sorbent casing 106, 108in a sealed manner, conditions or refurbishes the one or more sorbentcasing according to any of the implementations discussed above for theonsite primary embodiment, and informs the user or patient 12, 112 whenthe casing is ready to be removed from the conditioning or refurbishingdevice and reused within housing 80 of sorbent cartridge 100.

In the illustrated embodiment, user or patient 12, 112 loads sorbentcasings 106 and 108 into a cleaning chamber 352, which surrounds thecasings and holds them in a restrained manner. Although not illustrated,cleaning chamber 352 my provide a hinged lid that user or patient 12,112 opens to insert or remove casings 106 and 108. The lid is lockableto condition or refurbish the casings. In an embodiment, one or moresensor, such as a contact switch or proximity sensor is provided toensure that the lid is locked prior to any fluid flow through cleaningchamber 352. In the illustrated embodiment, cleaning chamber 352provides tapered or conical insert areas to form fit casings 106 and108, prevent leakage and to ensure that the casings are placed intocleaning chamber 352 in a desired orientation. In the illustratedembodiment, casings 106 and 108 are positioned so as to be tapered inthe same direction but could alternatively be positioned so as to betapered in opposite or otherwise different directions. Cleaning chamber352 introduces fluids to and recovers fluids from casings 106 and 108via nozzles 354 and funneled openings 356, so that the fluid is spreadto the entire intended surface of the casings.

At least one source of disinfectant 358 and at least one source ofregeneration fluid 360 are provided and in one embodiment housed withinsorbent conditioning or refurbishing device 350. In alternativeembodiments one or both of sources 358 or 360 is/are located outsidedevice 350. Disinfectant 358 and regenerated fluid 360 may be any of anytype described herein. Device 350 in the illustrated embodiment isfurther provided with a water, e.g., tap water, hookup 362 and a hot airblower 364. Fluids are drained to a drain 366.

In the illustrated embodiment, conditioning or refurbishing device 350is arranged fluidly such that disinfectant 358, regeneration fluid 360,water from hookup 362 and hot air from blower 364 may be directed tocasings 106 and 108 in either normal flow or reverse flow directions. Inalternative embodiments, some of these flow paths may be eliminated asdesired.

As illustrated: (i) valve 368 and pump 370 enable water to beselectively delivered to the upper side of cleaning chamber 352, whereinvalves 372 and 374 determine which (or both) casings 106 and 108 receivepressurized water from above; (ii) valve 376 and pump 378 enable waterto be selectively delivered to the lower side of cleaning chamber 352,wherein valves 380 and 382 determine which (or both) casings 106 and 108receive pressurized water from below; (iii) valve 384 and pump 386enable disinfectant to be selectively delivered to the upper side ofcleaning chamber 352, wherein valves 372 and 374 determine which (orboth) casings 106 and 108 receive pressurized disinfectant from above;(iv) valve 388 and pump 400 enable disinfectant to be selectivelydelivered to the lower side of cleaning chamber 352, wherein valves 380and 382 determine which (or both) casings 106 and 108 receivepressurized disinfectant from below; (v) valve 402 and pump 404 enableregeneration fluid to be selectively delivered to the upper side ofcleaning chamber 352, wherein valves 372 and 374 determine which (orboth) casings 106 and 108 receive pressurized regeneration fluid fromabove; (vi) valve 406 and pump 408 enable regeneration fluid to beselectively delivered to the lower side of cleaning chamber 352, whereinvalves 380 and 382 determine which (or both) casings 106 and 108 receivepressurized regeneration fluid from below; (vii) valves 410 and 412selectively allow hot air from blower 364 to be delivered to the upperand lower sides of cleaning chamber 352, respectively, wherein valves372, 374, 380 and 382 determine which one or both casings 106 and 108receive hot air for drying; and (viii) drain valves 414 and 416 incombination with valves 372, 374, 380 and 382 selectively allow anyfluid or hot air to be exhausted from either casing 106 and 108 and fromupper and/or lower sides, respectively, of cleaning chamber 352.

As illustrated, conductivity sensors 392, temperature sensors 394 and pHsensors 396 are located in strategic locations to sense desired fluidflow characteristics, e.g., to know when to stop a particular fluid flowas described in numerous ones of the implementations discussed above. Inthe illustrated embodiment, conductivity sensors 392, temperaturesensors 394 and pH sensors 396 are located along the branches leading todrain 366. Sensors 392, 394 and 396 include dashed lines indicatingpower and signal connections to control unit 420.

Sorbent conditioning or refurbishing device 350 is also illustrated ashaving heating coils 426, which may be electrically resistive heatingcoils under control of control unit 420. Feedback from temperaturesensors 394 to control unit 420 allows a heating algorithm employed bythe control unit to determine which heating coils 426 if any to energizeto heat the corresponding fluid to a desired temperature, e.g., up toabout 80° C.

In the illustrated embodiment, all pumps, valves, hot air blower 364 andheating coils 426 are operated by a control unit 420 of conditioning orrefurbishing device 350 as indicated by the dashed electrical lines. Thepumps are illustrated as peristaltic pumps but may alternatively bevolumetric or diaphragm pumps, gear pumps or other suitable fluid pump.A user interface 422 operating with control unit 420 is provided toenable user or patient 12, 112 to operate refurbishing device 350.Sensors 392, 394 and 396 likewise output to, and may receive power from,control unit 420.

In alternative embodiments sorbent conditioning or refurbishing device350 uses less pumps, e.g., (i) a single pump (two total) for each of theupper and lower sides of cleaning chamber 352 to handle all three ofwater, disinfecting agent and regeneration solution flow, or (ii) asingle pump for both of the upper and lower sides of cleaning chamber352 to handle all three of water, disinfecting agent and regenerationsolution flow on both upper and lower sides. Valves are arrangedaccordingly to selectively allow water, disinfecting agent orregeneration solution flow at a given time.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims. For example, while the specification has concentrated on theregeneration of zirconium sorbent materials, the conditioning orrefurbishing device 350, sorbent cartridge 100 and their associatedmethods of use (including any implementation method 160, 180, 200, 220,240, 260, 280, 300 and 320) may be applied to other materials thatperform the same or similar function as zirconium sorbent materials,such as titanium-based sorbent materials.

The invention is claimed as follows:
 1. A medical fluid delivery methodcomprising: providing a sorbent cartridge including zirconium phosphate(“ZP”) or zirconium oxide (“ZO”) for a treatment; and after thetreatment, refurbishing the ZP or ZO via the steps of regenerating thenon-disinfected ZP or ZO using an acid solution, disinfecting theregenerated ZP or ZO using a disinfecting agent, at least one of washingor filtering the regenerated and disinfected ZP or ZO, titrating thewashed or filtered ZP or ZO until a desired pH is reached in a titratedZP or ZO, at least one of washing or filtering the titrated ZP or ZOuntil a desired conductivity is reached in a rewashed or refiltered ZPor ZO, drying the rewashed or refiltered ZP or ZO, and sieving the driedZP or ZO.
 2. The medical fluid delivery method of claim 1, wherein atleast one of (a) the acid solution is HCl, H₂SO₄, H₃PO₄, HNO₃ or aceticacid or (b) the disinfecting agent (i) is sodium based, such asincluding NaOCl, (ii) is hydrogen based, such as including HOC₁, or(iii) includes isopropyl alcohol (“IPA”).
 3. The medical fluid deliverymethod of claim 1, wherein the desired pH is between and including 5.5to 8.5.
 4. The medical fluid delivery method of claim 1, wherein thedesired conductivity is below 50 μS/cm.
 5. The medical fluid deliverymethod of claim 1, wherein refurbishing the ZP or ZO includes combiningZP or ZO removed from multiple sorbent cartridges before regeneration.6. A medical fluid delivery method comprising: providing a sorbentcartridge including zirconium phosphate (“ZP”) or zirconium oxide (“ZO”)for a treatment; and after the treatment, refurbishing the ZP or ZO viaregenerating the non-disinfected ZP or ZO using an acid solution,disinfecting the regenerated ZP or ZO using a disinfecting agent, atleast one of washing or filtering the regenerated and disinfected ZP orZO, drying the washed or filtered ZP or ZO, and sieving the dried ZP orZO.
 7. The medical fluid delivery method of claim 6, wherein at leastone of (a) the acid solution is HCl, H₂SO₄, H₃PO₄, HNO₃ or acetic acidor (b) the disinfecting agent (i) is sodium based, such as includingNaOCl, (ii) is hydrogen based, such as including HOCl, or (iii) includesisopropyl alcohol (“IPA”).
 8. The medical fluid delivery method of claim6, wherein refurbishing the ZP or ZO includes combining ZP or ZO removedfrom multiple sorbent cartridges before regeneration.
 9. A medical fluiddelivery method comprising: providing a sorbent cartridge includingzirconium phosphate (“ZP”) or zirconium oxide (“ZO”) for a treatment;and after the treatment, refurbishing the ZP or ZO via regenerating thenon-disinfected ZP or ZO using a sodium based alkaline solution or asodium salt solution, disinfecting the regenerated ZP or ZO using adisinfecting agent, at least one of washing or filtering the regeneratedand disinfected ZP or ZO, titrating the washed or filtered ZP or ZOuntil a desired pH is reached in a titrated ZP or ZO, at least one ofwashing or filtering the titrated ZP or ZO until a desired conductivityis reached in a rewashed or refiltered ZP or ZO, drying the rewashed orrefiltered ZP or ZO, and sieving the dried ZP or ZO.
 10. The medicalfluid delivery method of claim 9, wherein at least one of (a) the sodiumbased alkaline solution or a sodium salt solution is NaOH, NaHCO₃,Na₂CO₃ or NaCl or (b) the disinfecting agent (i) is sodium based, suchas including NaOCl, (ii) is hydrogen based, such as including HOCl, or(iii) includes isopropyl alcohol (“IPA”).
 11. The medical fluid deliverymethod of claim 9, wherein the desired pH is between and including 5.5to 8.5.
 12. The medical fluid delivery method of claim 9, wherein thedesired conductivity is below 50 μS/cm.
 13. The medical fluid deliverymethod of claim 9, wherein refurbishing the ZP or ZO includes combiningZP or ZO removed from multiple sorbent cartridges before regeneration.14. A medical fluid delivery method comprising: providing a sorbentcartridge including zirconium phosphate (“ZP”) or zirconium oxide (“ZO”)for a treatment; and after the treatment, refurbishing the ZP or ZO viaregenerating the non-disinfected ZP or ZO using a sodium based alkalinesolution or a sodium salt solution, disinfecting the regenerated ZP orZO using a disinfecting agent, at least one of washing or filtering theregenerated and disinfected ZP or ZO, drying the washed or filtered ZPor ZO, and sieving the dried ZP or ZO.
 15. The medical fluid deliverymethod of claim 14, wherein at least one of (a) the sodium basedalkaline solution or a sodium salt solution is NaOH, NaHCO₃, Na₂CO₃ orNaCl or (b) the disinfecting agent (i) is sodium based, such asincluding NaOCl, (ii) is hydrogen based, such as including HOCl, or(iii) includes isopropyl alcohol (“IPA”).
 16. The medical fluid deliverymethod of claim 14, wherein refurbishing the ZP or ZO includes combiningZP or ZO removed from multiple sorbent cartridges before regeneration.